Color

28.1 THE COLOR SPECTRUM
Issac Newtown was the first to make a systematic study of color. If you shine a beam of white light through a triangular prism you can see te light bed and split up by color into a spectrum. Under white light white objects apear white and colored objects apear individual colors. If all the colors of the spectrum were to recombine the result will be white light. Black is similarly not a color its self, but is the absents of light.
external image lavatube-sunlight.jpgSunlight is an example of what is called white light.
28.2 COLOR BY REFLECTION
When white light shines on an object some of the light will be absorbed and some will be reflected. It depends on the material of the object.
external image Reflection1.gifhttp://www.kidport.com/RefLIb/science/Light/images/Reflection1.gif
The colors that are absorbed are not seen, but the colors that are reflected are seen. No other colors are possible besides the ones shining on the object.
28.3 COLOR BY TRANSMISSION
If white light shines through a transparent obbject some wavelengths witll be absorbed while others will pass through. The energy absorbed by the object will turn into heat and
cause the temperatur to increase slightly.
28.4 SUNLIGHT
Sun light is composite of all the visible frequencies as well as many others that we cannot see. The brightest colors have less intense frequencies.
28.5 MIXING COLORED LIGHT
The additive primary colors are red, blue, and green. When the three are added together, it produces white light.

Aditive colors animated gif
Aditive colors animated gif

28.6 COMPLEMENTARY COLORS
Complimentary colors are pairs of colors that togethere include each primary color. Cyan, which is blue and green light, is complimentary to red. When two complimentary colors are added together the result is white light.
Red + Green = Yellow
Red + Blue = Magenta
Red + Cyan = White
Blue
+ Green = Cyan
Magenta + Green = White
Yellow
+ Blue = White
28.7 MIXING COLORED PIGMENTS

Pigments absorbe the complimentary colors to the ones that they reflect. A cyan pigment will absorb red light and reflect blue and green. If two pigments are mixed the resulting pigment wil absorb all colors absorbed by either of the pigments, this is known as mixing by subtraction. If yellow pigment is mixed with cyam pigment the resulting pigment will absorb both blue and red and will reflect green light. The subtractive primary colors are cyan, magenta and yellow.
28.8 WHY THE SKY IS BLUE
external image blue%20sky%20sailboat.jpghttp://pinker.wjh.harvard.edu/photos/cape_cod/images/blue%20sky%20sailboat.jpg
The sky is blue because microscopic particles in the atmosphere some of the light will be absored and scattered by the particles it passes through. The shortest wavelengths of light are violet and blue, causing the sky to appear to be blue. The remaining longer wavelengths cause the sun to appear yellow.

28.9 WHY SUNSETS ARE RED http://supergood365.com/YourKeyToSuccess/images/stories/Sized%20sunsets%20540px/sunset-red-2.jpg


external image sunset-red-2.jpg
Sunsets are red because when the sun is low in the sky the light has a much longer path to reach you eyes. The longer wavelengths will be scattered leaving only red and oranger light to reach the surface of Earth. Therefore, when light passes through a thick atmosphere, light of the lower frequencies is transmitted while light of the higher frequencies is scattered. The colors of the sun and sky are consistent with our rules for color mixing. the relative amounts of scattering depends on atmospheric conditions, which change from day to day and give us a variety of sunsets.
external image PC0608_water%20copy.jpg 28.10 WHY WATER IS GREENISH BLUE
Water is a greenish blue becaus the water absorbs a very small amount of red light. In a large amount of water there is an absents of red, making the water appear to be cyan. Water is transparent to nearly all the visible frequencies of light. water molecules absorb infrared waves because they resonate to the frequencies of infrared. Infrared is a strong component of the sunlight that warms water. In summary, the sky is blue because blue from sunlight is remitted in all direction is by molecules in the atmosphere. Water is greenish blue because red is absored by molecules in the water. the colors of things depend on what colors are refleced by molecules and also by colors are absored by molecules.

28.11 THE ATOMIC COLOR CODE-ATOMIC SPECTRA
The pattern of light seen through an spectroscope is called a line of spectrum. It is different for every element.

spectrum.jpg

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